Car airbags can seriously damage your hearing.
The safety devices are inflated using an explosive burst of gas that makes an incredibly loud sound, so loud it can cause instant damage to the ear.
To get around this problem, engineers at Mercedes-Benz have come up with an ingenious solution. When the airbag system detects a collision, it initially sends out a short noise signal that triggers the ‘stapedius reflex’, an involuntary muscle movement that protects your ears from excessive sound levels.
So when the airbags fire, a fraction of a second later, no damage is done. Clever stuff!
Read the original article, originally reported in The Knowledge, now in Hackaday